ICP-AES法测定铍铝合金中银、锗和钴量

建立了电感耦合等离子体原子发射光谱法测定铍铝合金中银、锗和钴量的分析方法。采用硫酸(5+95)10 mL和硝酸(1+1)10 mL溶解试样。研究了元素分析谱线的选择、铍和铝基体对银、锗和钴测定的干扰等实验条件,并对仪器工作参数的选择进行了优化,确定了最佳的实验条件,各元素分析谱线依次为Ag 338.289 nm、Ge 209.426 nm、Co 238.892 nm,建立的校准曲线各元素的线性相关系数均在0.9995以上。铍铝合金样品分析中,加标回收率为97%~103%,重复测定结果的相对标准偏差为0.70%~0.90%(n=8)。     

ICP-OES法测定铝-锌-铟合金中铟、镁、钛、铁、硅合金元素的含量

采用电感耦合等离子体发射光谱(ICP-OES)法测定铝-锌-铟合金中铟、镁、钛、铁和硅合金元素含量。样品选用盐酸(1+1)消解,对待测各元素选择光谱干扰较少的分析谱线,同时采用基体匹配消除基体影响。方法检出限(3 s)在1~9μg·L-1之间,方法回收率在96%~104%之间,各元素含量大于0.010%时的测定值的相对标准偏差(n=11)小于2.0%。     

压力消解ICP-AES法对润滑油异构脱蜡催化剂中铂、钯含量的测试

采用高压消解技术,使用盐酸、硝酸和氢氟酸对润滑油异构脱蜡催化剂进行处理,制备测定样品水溶液,选择Pt波长214.423 nm和Pd波长340.458 nm作分析线,电感耦合等离子体原子发射光谱仪(ICP-AES)进行测定,对压力消解条件进行确定,对待测元素的分析谱线选择进行分析。结果表明,各元素校准曲线线性相关系数均不小于0.999 00,检出限Pt为0.030 12 mg·L^-1,Pd为0.015 21 mg·L^-1。按照实验方法测定润滑油异构脱蜡催化剂样品中Pt、Pd结果的相对标准偏差(RSD,n=6)均小于1%,回收率98.0%~103.0%,测试方法准确可靠。     

电感耦合等离子体原子发射光谱法测定循环冷却水系统污垢中铁、钙、镁元素的含量

采用电感耦合等离子体原子发射光谱法测定循环冷却水系统污垢中铁、钙、镁元素的含量。选用5mL硝酸(1:1)与5mL盐酸10滴过氧化氢作为溶剂溶解样品,铁、钙、镁的分析谱线分别为259.94nm、317.93nm、279.08nm,各元素的工作曲线线性良好,线性相关系数均大于0.9999,测定结果的相对标准偏差分别为0.99%,0.38%,0.28%(n=6)。加标回收率在93.2%~97.1%之间。该方法的精密度、准确度均能满足环冷却水系统污垢中铁、钙、镁元素的含量分析规范要求。     

ICP-AES同时测定锑矿石样品中的5种伴生元素

文章针对锑矿石中锑元素易水解易挥发的特性探讨了用硝酸分解有机物与硫化物,逆王水低温溶解样品,电感耦合等离子体发射光谱对锑矿石中Cu 324.754 nm、Pb 220.353 nm、Zn2 13.856 nm、Sb 231.147 nm、As 189.042 nm同时测定的仪器工作条件及各元素的分析谱线背景校正方法,基本解决了基体干扰和待测元素之间的干扰问题。建立的方法用于锑矿石样品中铜铅锌锑砷的分析,方法检出限为铜0.0002%、铅0.0014%、锌0.0001%、锑0.002%、砷0.003%,相对标准偏差(RSD,n=12)1%,加标回收率为97.2%~103.1%。通过与其它分析检测方法比对,结果吻合,且可在线同时测定多种元素,检测线性范围宽,快速简捷,准确度高。     

ICP-OES法测定六方氮化硼中钙、镁、钠、铁的含量

建立了微波消解-ICP-OES测定六方氮化硼中钙、镁、钠、铁的检测方法,优化了样品前处理方法和仪器参数。结果表明,标准溶液各元素的质量浓度与光谱强度绘制的标准曲线相关系数均大于0.9995。铁、镁、钙的检出限为0.0015μg/m L,钠的检出限为0.0030μg/m L。各元素加标回收率在90%~110%之间,测定结果的相对标准偏差均小于2%,用该方法对氮化硼标准样品进行测定,测定结果在标准值的允许差范围内。     

总汞及无机砷在2种鲍鱼不同组织含量分布研究

利用微波消解-氢化物发生原子荧光光谱法,测定不同产地皱纹盘鲍与杂交鲍内脏及肌肉中总汞及无机砷的含量,汞的检出限为0.002 mg/kg,回收率87.5%~97.5%,RSD<5%,无机砷检出限为0.05 mg/kg,回收率在95.5%~102.5%之间,RSD<5%,各元素的线性关系均良好(r=0.9990~0.9999),该方法的精密度和准确性良好。检测结果表明,两种鲍鱼内脏及肌肉富集汞与无机砷的能力具有明显的差异,内脏高于肌肉中的含量,无机砷含量远大于汞的含量。     

微波消解-ICP-MS法测定红景天胶囊中的砷、汞和铅

采用了硝酸-过氧化氢混合酸微波消解法前处理红景天胶囊样品,电感耦合等离子体质谱法同时测定红景天胶囊中As,Hg和Pb的含量。完善了样品前处理条件,优化了仪器工作参数,选择Rh、Re作为内标,有效克服了基体效应和仪器波动的影响。方法各元素加标回收率在102.7%~106.0%之间,精密度RSD在4.70%~5.55%之间,砷、汞、铅的检出限(3S)分别为0.004 5、0.000 6、0.003 3μg·g-1。     

高效液相色谱法同时测定化妆品中12种防腐剂

采用高效液相色谱法同时检测化妆品中12种防腐剂的含量。C18色谱柱(250 mm×4.6 mm×5μm)为分析柱,甲醇+乙腈+0.02 mol·L-1磷酸二氢钠(pH=3.5)为流动相,梯度洗脱。2-溴-2-硝基丙烷-1,3-二醇和苯甲醇检测波长为210 nm;甲基氯异噻唑啉酮和甲基异噻唑啉酮检测波长为280 nm;其它组分检测波长为254 nm。结果表明各组分在浓度为4.242~299.0 mg/L范围内与目标峰面积均呈较好的线性关系,R均大于0.9999。加标回收率在92.6%~108%之间,各组分的相对标准偏差(n=7)在1.2%~3.1%之间。方法相对《化妆品卫生规范》相比,更简单、易操作、实用性更强,适用于化妆品中多种防腐剂的同时测定。     

ICP-AES测定化学实验室自来水中重金属元素含量

采用电感耦合等离子体原子发射光谱法(ICP-AES)测定化学实验室自来水中铅、镉、铬、砷、铜、镍、锌7种重金属元素的含量。对仪器的工作条件进行优化,选择各元素的分析线,测定各元素的检出限。对化学实验室自来水样品进行分析,7种重金属元素测定的相对标准偏差RSD(n=9)在0.92%~4.2%之间。     

Aluminum,Arsenic, Beryllium,Cadmium, Chromium,Cobalt, Copper,Iron, Lead,Mercury, Molybdenum,Nickel, Platinum,Thallium, Titanium,Vanadium, and Zinc: Molecular Aspects in Experimental Liver Injury

Experimental liver injury with hepatocelluar necrosis and abnormal liver tests is caused by exposure to heavy metals (HMs) like aluminum, arsenic, beryllium, cadmium, chromium, cobalt, copper, iron, lead, mercury, molybdenum, nickel, platinum, thallium, titanium, vanadium, and zinc. As pollutants, HMs disturb the ecosystem, and as these substances are toxic, they may affect the health of humans and animals. HMs are not biodegradable and may be deposited preferentially in the liver. The use of animal models can help identify molecular and mechanistic steps leading to the injury. HMs commonly initiate hepatocellular overproduction of ROS (reactive oxygen species) due to oxidative stress, resulting in covalent binding of radicals to macromolecular proteins or lipids existing in membranes of subcellular organelles. Liver injury is facilitated by iron via the Fenton reaction, providing ROS, and is triggered if protective antioxidant systems are exhausted. Ferroptosis syn pyroptosis was recently introduced as mechanistic concept in explanations of nickel (Ni) liver injury. NiCl₂ causes increased iron deposition in the liver, upregulation of cyclooxygenase 2 (COX-2) protein and mRNA expression levels, downregulation of glutathione eroxidase 4 (GPX4), ferritin heavy chain 1 (FTH1), nuclear receptor coactivator 4 (NCOA4) protein, and mRNA expression levels. Nickel may cause hepatic injury through mitochondrial damage and ferroptosis, defined as mechanism of iron-dependent cell death, similar to glutamate-induced excitotoxicity but likely distinct from apoptosis, necrosis, and autophagy. Under discussion were additional mechanistic concepts of hepatocellular uptake and biliary excretion of mercury in exposed animals. For instance, the organic anion transporter 3 (Oat3) and the multidrug resistance-associated protein 2 (Mrp2) were involved in the hepatic handling of mercury. Mercury treatment modified the expression of Mrp2 and Oat3 as assessed by immunoblotting, partially explaining its impaired biliary excretion. Concomitantly, a decrease in Oat3 abundance in the hepatocyte plasma membranes was observed that limits the hepatic uptake of mercury ions. Most importantly and shown for the first time in liver injury caused by HMs, titanium changed the diversity of gut microbiota and modified their metabolic functions, leading to increased generation of lipopolysaccharides (LPS). As endotoxins, LPS may trigger and perpetuate the liver injury at the level of gut-liver. In sum, mechanistic and molecular steps of experimental liver injury due to HM administration are complex, with ROS as the key promotional compound. However, additional concepts such as iron used in the Fenton reaction, ferroptosis, modification of transporter systems, and endotoxins derived from diversity of intestinal bacteria at the gut-liver level merit further consideration.     

THERMOPLASTIC,FLEXIBLE, AND RECYCLABLE COMPOSITES,DESIGN, PREPARATION,AND CHARACTERIZATION

Glass fiber reinforced composites based on thermosets are the traditional materials used for many applications due to their good mechanical properties. The non-recyclability of these materials has led to the necessity to develop thermoplastic composites and industrial processes for their manufacture [1]. The present paper deals with the preparation of thermoplastic pre-pregs unidirectionally reinforced with Twarn® and their mechanical characterization.     

DUO-ICP-AES测定精对苯二甲酸中的钴、铬、铁、锰、钼、镍、钛

采用DUO-ICP-AES同时测定精对苯二甲酸中钴、铬、铁、锰、钼、镍、钛,并对仪器的分析线选择、背景校正、入射功率、雾化器压力、辅助气流量、冷却气流量、蠕动泵转速的影响及共存元素的干扰、硝酸铯灰化助剂等因素进行了详细的研究。方法的检测限:钴0.0097 mg/L;铬0.0021 mg/L;铁0.0078 mg/L;锰0.0012 mg/L;钼0.0027 mg/L;镍0.016 mg/L;钛0.0027 mg/L,回收率和精密度分别为93.0%～99.5%和0.37%～3.2%。该方法快速简便,具有良好的精密度和准确度,适用于进出口精对苯二甲酸的日常检验。     

Pd-, Ni-, Fe-, and Co-Catalyzed Cross-Couplings Using Functionalized Zn-, Mg-, Fe-, and In-Organometallics

The development of new methods for preparing polyfunctional organometallics has made a broad range of such reagents available for various transition metal-catalyzed cross-couplings. An overview of the most general preparation methods will be presented. Applications to practical cross-coupling procedures will be covered, emphasizing the functional group compatibility and the reaction scope.